The present invention is related to oilfield top drives and power swivels, each of which employs a washpipe dual seal assembly to contain high pressure drilling fluids.
Conventional seal assemblies are heat generating by nature and are typically rated to contain 5000 psi but in practical application will only support that pressure level for brief periods such as 5 hours.
A need exists for a top drive or power swivel with a washpipe dual seal assembly capable of containing much higher pressures reliably, for example 10,000 psi for hundreds of hours.
A need exists for an automatic lubricating seal assembly which does not require manual refilling or an additional long hose or more than 4 long hoses total from a remote hydraulic power unit.
The present embodiments are detailed below with reference to the listed Figures.